Hello to Billy and Melanie , welcome to Small Pets 
They will be very shy at first. They are shy, prey animals ( they assume that any minute something will swoop in and eat them) . They've been introduced to a new environment , new sounds, new smells. The only constant is the other guinea-pig.
Part of the charm of guineas (apart from the fact they are as Thick as Mince
) is that they are the gentlest little animals ever . And even though they have very sharp teeth they are very rarely biters.
My pigs almost never drank water from a bottle (except at 3am when they were in the next bedroom to me !) But from the amount of pee they produced there was no doubt they were getting enough fluid.
But offer clean fresh water daily , scrub the water bottle every week. Even if they choose to ignore it !
Hay is essential. They need a wedge of hay about the size of the pig , but they eat,sleep. pee,pooh and play so you're looking at offering unlimited hay .
Pellets contain Vit C .
There's loads of veg you can offer them.
Some they can have limited , some are 'No'
Root veg (carrot, parsnip) are high in sugar so give sparingly . Mine liked the leafy carrot but not carrot peel
Sweetcorn in leaf (again quite high in sugar)
Herbs- parsley , mint ,coriander
Dark greens-brocilli, kale,cabbage ,cavelo nero (limited due to risk of bladder stones)
Salad- cucumber, spinach (limited) cos lettuce ,romaine, chinese leaf, celery but no strings. Loved the leaves
Not to give
iceberg lettuce, onions,mushrooms, any potato
Wild plants- dandelions, grass, limited clover . All fresh cut , rinse and dry . No lawnmower cuttings .
No buttercups, daisies, bulb plants
Fruit - (limited)
small bits apple, watermelon ( especially the rind with a bit of fruit left) banana (skin+fruit) strawberries and leaves, blueberries. Some pigs like a slice of orange .
Give a few bits for variety and they'll choose .
They can be fussy 
Mine wouldn't touch lambs lettuce but hoovered up spinach.
Wouldn't eat peelings .
Only ate kale if they were at the point of starvation but loved Cavelo Nero .
Acted like I'd poisoned them when I offered them a bit of pumpkin !
Sawdust and shavings aren't good for guineas - it can dry their fur and paws . Plus they are respiratory sensitive , their little noses are at floor level.
Lots of pig keepers use equine bedding like Megazorb or Auboise .
I used Ecobale (chopped cardboard) in their outdoor house . Or just newspaper on the floor . You can use fleece but its a pain to wash . If you do get a petbag to save your machine and a scentless detergent .
Piggies are lovely , full of character .
And the noises
. Look on YouTube for videos . It is a good way of 'reading' their mood .
I had some Singing Pigs (its like a bird chirping) There's no known reason why they sing.